July 12
Battle of Porto Alegre
On the night of the eleventh Composite Squadron C, Vice Almirante Peachas commanding, left Rio de Janeiro. His mission was to offer fire-support to the Brazilian forces trying to escape the RSAA advanced elements pushing northwards. Unknown to Peachas was the fact the Brazilian Naval HQ was sending this force of ships not only to show the Brazilian Navy was not out of the war as most African officers thought but also as a diversion to aid the Argentine naval operations taking place further south. The battleship Sao Paulo was escorted by the old light cruisers Rio Grande do Sul and Amazonas (ex-USS New Orleans) and four Margay Class destroyers (Pantera, Lince, Tigre and Leopardo).
EMB-32 Fighter
Spotted at 05:24 by an RSAF AeroDynamics RBW-9B "Dragonfly" seaplane the force called for air support and at 07:12 eight F-4 (EMBRAER EMB-32) and ten F-39 (EMBRAER EMB-36) fighters appeared over the fleet. Only five minutes later as the fighters got into position at 5,000 feet an RSAF attack force of seven Foller Fo 122 MK III "Kingklip" torpedo bombers escorted by six DeBroek F-3C "Warhawk" fighters above made an attack from wave-top height. The Brazilian fleet lacked enough modern medium caliber AA guns to put up a barrage but at least the escorting destroyers opened on the attackers with their 37mm cannons and HMG but only one Fo 122 was shot down before the planes dropped their fish. No torpedoes hit but the formation was in disarray and the Sao Paulo nearly rammed the destroyer Lince at one point. The Brazilian fighters managed to shoot down two further "Kingklips" but lost three of their number to the superior RSAF fighter pilots who came in at 6,000 feet.
At 10:08 six old Villant B-8CN "Pig" biplane bombers made an attack from 4,000 feet. All but one was hacked from the skies as more Brazilian fighters had arrived over their fleet earlier. At 10:40 the fighters had to leave for refuelling but the promised replacements never arrived and by noon three AeroDynamics RBW-9B "Dragonfly" seaplanes were tracking the force outside of gun range. Vice Almirante Peachas was very worried and radioed Naval HQ whether he should turn back [Note 1]. The reply received left no room for interpretation: Your mission is of great importance for all our war efforts. You are ordered to complete the mission; you cannot turn back until the mission is fulfilled. Brazil trusts in you and your men. You must defeat the enemy!
Rear Admiral Hien aboard the RSAN Mauritius had sailed that morning to intercept the Brazilian force. His command comprised 3rd Battle Squadron 1st Division (flagship RSAN Mauritius and RSAN Réunion), elements of the 4th Coast-Guard Flotilla (RSAN Gungnir and RSAN Ymir) and 2nd Coast-Guard Flotilla (RSAN Nagelring, which was already in the area on coastal bombardment duties). Hien had been promised destroyer support but it was clear as he closed in on the enemy that none would arrive in time [Note 2]. According to the flagships log he planned to engage with heavy guns in good old fashion and knock-out the antique cruisers and sink the Sao Paulo. Eventually at 14:20 the RSAN Saber from the 10th Destroyer Flotilla 2nd Division arrived having been detached from convoy duty.
At 14:49 both sides spotted each other at a range of around 18,000 yards through the rain and heavy swell some six miles off the coast. In line astern RSAN Mauritius and RSAN Réunion turned twenty degrees to starboard to open the arcs and to cross ahead of the enemy. The Sao Paulo answered by turning to port bringing her on a nearly parallel course while the destroyers Pantera, Lince, Tigre and Leopardo in line astern began a torpedo attack. The two African Coastal Defence Ships remained in line astern and followed the battleships to concentrate their fire on the two old Brazilian cruisers astern of the Sao Paulo. The Ymir stayed to starboard and aft of the battle line but opened on the approaching Brazilians with her forward turrets while the destroyer RSAN Saber headed towards the Brazilian line head-on to reduce her profile. Meanwhile RSAN Mauritius and RSAN Réunion and the Sao Paulo exchanged their first salvoes. Both sides failed to score any hits but the weight of the African gunfire was scoring several straddles.
At 15:06 the RSAN battle line broke up as they avoided the twenty-four torpedoes fired at them by the Brazilian destroyers at a range of 2,500 yards. RSAN Saber came under a deluge of 4.7in shells and no less than four hit the forward hull wrecking B gun and destroying most of the bridge severing the controls from the DCT. Still the Saber managed to fire four torpedoes and her aft turrets under local control. She was rewarded with a hit against the Lince amidships. RSAN Mauritius and RSAN Réunion only had casemated secondary guns, the forward ones were washed out by the seas but they put out a heavy, but inaccurate, barrage. Splinters from near-misses sprayed the bridge of the Tigre and RSAN Nagelring managed to score two 88mm hits on her aft (knocking out Y turret and dislodging the light belt armour aft). RSAN Gungnir fired some 105mm rounds but her wild manoeuvring to avoid the torpedoes made her fire-control useless.
Out of the 24 Brazilian torpedoes fired three hit, two hit RSAN Réunion (one just aft of Y turret tearing the outer propeller shaft lose and causing serious flooding aft and shorting several electrical circuits putting Y turret out of action, the other hit shortly afterwards abreast B turret but it was a dud) and the other, after passing through the African battle line, hit RSAN Ymir forward causing severe flooding. She hauled out of line and retreated to the south as her damage repair parties struggled to reinforce the bulkheads and lay on extra pumps. The Brazilian triple 4.7in turrets on the large destroyers pumped out shells and although several hit the battleships they caused no serious damage and as the Leopardo turned to escape a 150mm shell from Mauritius hit and wrecked X turret igniting two charges which completely destroyed the turret and started a massive fire aft. Two minutes later her after magazine exploded and the destroyer vanished into a giant fireball. RSAN Saber also retired taking on water in the forward boiler room but her after guns continued firing at the fleeing destroyers.
While all this was happening Vice Almirante Peachas saw his chance to escape and he turned northwest with the cruiser Rio Grande do Sul providing smoke cover. He radioed to Naval HQ that his forces had sunk an African destroyer and crippled a battleship. In fact the two remaining African Coastal Defence Ships (RSAN Nagelring and RSAN Gungnir) quickly reformed into a line astern formation and turned after the cruiser Amazonas which they caught up with, testimony of their superior speed. At a range of 13,500 yards they began concentrated fire. Numerous splashes and interference hindered accurate aiming but no less than ten 210 and 250mm shells hit the cruiser within fifteen minutes [Note 3] although the cruiser did hit RSAN Gungnir once (on the main deck causing some damage and wounding ten sailors) and straddled Nagelring twice. The Amazonas began to slow and after two secondary explosions aft she took on a noticeable list to port. The South Africans continued firing and scored two more hits. Finally the Amazonas ceased firing at 15:45 and the African ships closed in for the kill. At 5,400 yards range RSAN Nagelring fired three torpedoes, two hit amidships and the cruiser swiftly sank at 15:57.
Meanwhile the Rio Grande do Sul tried to lay a smoke screen to shield the Sao Paulo until the destroyers had reformed but the strong winds negated her efforts. Then, after sinking the Amazonas, the African CDS opened fire upon her at 15:52 but she escaped into a rain squall. No hits were observed but one 210mm calibre shell did hit aft exploding on contact with the armoured deck causing several casualties and damaging Y turret´s hoist.
While the smaller units fought their own battle Rear Admiral Hien ordered his two battleships to concentrate on the Sao Paulo, ignoring the cruiser. Both sides exchanged fire at a range of 19,500 yards at times. It was a battle the Sao Paulo was doomed to lose. No less than eleven 15in hits were obtained on the Sao Paulo and she began to slow [Note 4]. With two turrets knocked out she had no chance to outshoot the two African battleships but her gunner mates kept up a stiff defence and scored three hits against the Mauritius in return [Note 5]. Despite her torpedo damage the Réunion had kept up with her sister but finally she slowed and fell behind, her captain forced to reduce revolutions and allowing his damage control crews to save his ship. Her gun crews, however, kept on firing. RSAN Mauritius could easily match the Sao Paulo´s speed and soon they were roughly parallel again. Vice Almirante Peachas tried to turn away another time but he could not escape the withering fire. By now the three remaining Brazilian destroyers were reforming to strike on the African s starboard side and Rear Admiral Hien at 15:59 disengaged after a final salvo (which straddled the target and one 15in shell visibly hit aft) and turned to meet the new threat on his starboard bow.
[img]http://wesworld.jk-clan.de/schiffbilder/CDS Nagelring.jpg[/img]
RSAN Réunion with the RSAN Nagelring and RSAN Gungnir close-by for mutual support turned south and began long-range firing on the Brazilian destroyers (the range varied from 20,000 to 16,000 yards in the rough weather) while the RSAN Mauritius fired full salvoes to force the Brazilian destroyers to keep away. No hits were obtained but the heavy concentration of fire unnerved the Brazilian skippers and they pulled back and splinters did cause some superficial damage. With the Tigre laying a smokescreen the other two destroyers tried to make a torpedo attack at 16:27 [Note 6] but Vice Almirante Peachas struggling at only 10kts to get to safety recalled the destroyers to form a defensive screen as dusk fell.
Notes:
[Note 1] All radio messages were intercepted and de-coded by the RSAN Naval Intelligence outstation at Rio Grande thus keeping Rear Admiral Hien informed throughout the battle.
[Note 2] Unknown to Rear Admiral Hien Argentine surface forces were striking a convoy to the south east and he did not learn of this until 14:10 and at the same time a weather report confirmed the bad weather would continue with another storm closing in.
[Note 3] Nearly all of the hits pierced the main deck armour to explode inside the boiler rooms and the engine rooms. Those that did not were either duds or exploded on contact causing blast damage and killing several repair parties. One 5in charge magazine exploded wrecking the two after broadside 5in mounts and the other secondary explosion was the 3in AA gun ready-use ammunition ignited by the fire started by an earlier hit. Another 5in broadside mount received a direct hit and the hull was holed in three places just above the waterline, another 210mm shell pierced the forward grating destroying the uptakes and depriving the boilers of draught air.
[Note 4] These eleven 15in hits were obtained from 15:24 to 15:50 (ignoring the final hit at 15:59 which wrecked the after CT tube), seven shells penetrated the main deck. One destroying No.2 boiler room and wrecking the distilling plant above, one hit S3 4.7in casemate from above killing all within and the plug penetrated into the armoured deck below causing no damage below it, the after engine room was hit twice and splinters and the remains of one 15in shell entered the space (the steam lines were broken and ten crewmen injured), a hit abreast X turret started a fire and two more aft of C turret wrecked the mess spaces and started several fires forcing two 4.7in casemates to be abandoned. Two more 15in shells that hit were duds but one smashed one of the legs of the tripod foremast. The three remaining hits were one on X turret s roof blasting out the rear plate and dislodging the faceplate (the rangefinder turret atop the turret was blown overboard killing the five occupants). All inside were killed and the flash ignited a charge in the hoist. Another 15in shell hit the upper belt near C turret and pierced it causing severe damage behind, and shortly afterwards another 15in shell smashed into C turret s faceplate cracking it and jamming the guns. Three men inside were killed by splinters that entered through the gun ports.
[Note 5] The three Brazilian 12in hits were scored at 15:35, 15:47 and 15:51. The hit at 15:35 penetrated the main deck just behind X turret and it exploded behind the barbette causing scabbing and starting a serious fire. The hit at 15:47 hit the main belt, the plug ricocheted off but the backing plates were badly damaged, the final shell hit P5 150mm casemate piercing the faceplate and killing everyone inside. The internal bulkheads held the blast and the trunk to the magazine below also held.
[Note 6] The Pantera and Lince had not been able to launch all their torpedoes during the early attack and still had a total of eight torpedoes available for a second wave.
[Note 7] Damage ratings after the battle had calmed down:
RSAN Mauritius rated 93%
RSAN Réunion rated 80%
RSAN Gungnir rated 99%
RSAN Ymir rated 63%
RSAN Nagelring rated 98%
RSAN Saber rated 70%
Sao Paulo rated 61%
Rio Grande do Sul rated 93%
Amazonas rated 0% (sunk)
Pantera rated 96%
Lince rated 93%
Tigre rated 90%
Leopardo rated 0% (sunk)